Polyamides, otherwise known as nylons, are well known and have achieved great commercial success. While most polyamides are used in the manufacture of fibers and/or bristles, newer and/or modified polyamides are finding increasing use and demand in applications where parts are manufactured through a molding process, e.g. injection molding. Additionally, the development of polyamide blends with rubber polymers and copolymers as well as with other thermoplastics has greatly expanded the property profile and thus potential end use applications for polyamides.
However, in spite of the advances in polyamide technology and development, the utility of polyamides is still limited by their extreme sensitivity to moisture. As a result of their exposure to moisture, either by direct immersion or water vapor itself, e.g. high humidity, polyamides tend to gain weight and expand or swell. Consequently, those end use applications wherein weight and, more importantly, dimensional stability are required and critical are still out of reach of the polyamides and polyamide blends.
The present invention enables one to make polyamide compositions and polyamide blend compositions which have significantly reduced water absorption. Thus these compositions may be employed in those end use applications wherein retention of the dimensional specification of parts is critical.